2009 Data Center Efficiency Summit Case Studies

See below for case studies from the 2009 Data Center Energy Efficiency Summit hosted by NetApp.

Lab Setpoint Increase, Cisco

Based on industry understandings of potential energy savings by raising cooling system setpoint temperature, Cisco’s DCSTG lab team has undertaken this case study to confirm these understandings, and how they might relate to Cisco data center facilities on the company’s San Jose campus. Various measures were implemented prior to raising setpoints in Cisco San Jose Building SJC07. The project started in September 2008. Power meters were installed to augment facilities metering. Blanking panels and over 200 temperature sensors were installed in Lab D. Floor grills were reallocated to eliminate overcool areas and hot spots in the lab. Simulations were performed at each step to estimate effectiveness and measure outcome. Data from power meters, temperature sensors, and BMS were collected and stored in OSI database. Over time, the setpoints were then increased in steps in Lab D and other labs from 68-72º to 78-80º F and the chilled water setpoint was increased from 44 to 48º F. It is estimated that 3-5% of cooling power savings have been achieved per one degree of chilled water temperature increase. Overall payback time was about six to twelve months.

This case study demonstrates RagingWire’s approach to improving efficiency of the chilled water and cooling system from end to end. The case study describes RagingWire’s approach to the ASHRAE standards and the air equation while maintaining a fault tolerant, concurrently maintainable data center. The energy conservation measures (ECM) have demonstrated a savings of 2,123,930 kWh/year for the current load, and an estimated additional 3,500,000 kWh/year on full build out.

Control of Computer Room Air Conditioning Using Sensors in the IT Equipment, Intel

This goal of this demonstration was to show how sensors in IT equipment could be accessed and used to directly control computer room air conditioning. The data provided from the sensors is available on the IT network and the challenge for this project was to connect this information to the computer room air handler’s control system. A control strategy was developed to enable separate control of the chilled water flow and the fans in the computer room air handlers. By using these existing sensors in the IT equipment, an additional control system is eliminated (or could be redundant) and optimal cooling can be provided saving significant energy. Intel hosted the demonstration in its Santa Clara, CA data center. Intel collaborated with IBM, HP, Emerson, Wunderlich-Malec Engineers, FieldServer Technologies, and LBNL to install the necessary components and develop the new control scheme. LBNL also validated the results of the demonstration.

The application utilization for larger server farms in today’s data centers is typically highly volatile due to many factors. Time of day usage patterns, promotions and advertisements, and unexpected events all cause spikes in demand, both planned and unplanned. As a result, data center operators have to deal with a high level of uncertainty when planning capacity. They mitigate the risk of a service outage by over-provisioning equipment and keeping their entire pool of servers “always on”. The result is an average utilization below 20% with occasional peaks of 85-90%.

Control of Computer Room Air Handlers Using Wireless Sensors, Franchise Tax Board

This project demonstrated how a wireless sensing network, provided by Federspiel Controls, can be used to directly control computer room air conditioning devices. Several air management improvement strategies were also implemented, e.g., air curtains, that worked together with the control system to achieve significant energy savings. Using the wireless sensors, fan speed and chilled water flow were adjusted to provide the optimal amount of cooling to the IT equipment. Changes were made incrementally to compare the effect of each measure on energy performance. Annual data center energy consumption was reduced by 475,239 kWh, which is over 21% of its original baseline energy use. This energy reduction results in eliminating more than 400 Tons of CO2 greenhouse gas emissions per year. Total project cost amounted to $134,057 with an annual savings of $42,772 resulting in a payback period of 2 ¼ years, after including rebates. The demonstration was hosted at California’s State Franchise Tax Board data center in Sacramento, CA.